DE4314625C1 - Use of copper@-titanium@ alloy - to mfr. wires or profiles for parts of spectacles - Google Patents

Abstract

Use of a Cu-Ti-X alloy to mfr. wires or profiles for parts of spectacles is claimed. The alloy comprises 2.0-3.5% Ti, X= 0.1-1.0% Fe, or 0.05-0.5% Zr, or 0.5-1.5% Mg, a balance of Cu and usual impurities. The vacuum-cast and extruded alloy has a hardness of at least 200 HV10 after cold forming; homogenising annealing between 850-1000 deg C for 10 mins.-10hrs. rapid cooling at 20 deg C/S-150 deg C/s, and cold forming between 50 and 90% degree of forming. Amt. of Fe present is 0.3-0.6%, Zr is 0.1-0.5% and Mg is 0.8-1.2%. Subsequent cold forming of at least 20% is carried out. ADVANTAGE - The alloy has suitable, mechanical strength.

Description

The invention relates to the use of copper-titanium-iron, Copper-titanium-zirconium and copper-titanium-magnesium alloys for the production of wires and profiles for spectacle parts. Under Glasses parts should in particular glasses, glasses frames, Understand the eye edge profiles, nose piece and eyeglass hinges become.

From a good alloy of glasses, u. a. sufficient mechanical Strength (tensile strength <600, hardness 180-280 HV), a low modulus of elasticity, sufficient resistance to softening, an attractive visual appearance, good polishability and Coatability expected.

Metallic commodities such. B. parts of glasses Alloys containing nickel can cause skin allergies on contact trigger. Nickel allergies are now among the most common occurring contact allergies. Especially the optical wire processing Industry is therefore looking for nickel-free replacement materials for the production of glasses hills, eye edge profiles, nose pieces and hinges. Nickel-free alloys are said to Properties of the nickel-containing nickel silver alloys previously used (e.g. CuNi18Zn20) can be substituted. In doing so high demands on cold forming ability and handling behavior posed. The usual liaison work is brazing at temperatures between 620 and 680 ° C. The structure the parts of the glasses experience one at the connection points Short-term annealing and thus a softening. To the functionality of a piece of glasses even after the connection work  guarantee with hard solder, it is a wish of the eyeglass frame manufacturers, that the hardness does not fall below 150 HV.

The invention is therefore based on the object for the above Propose a copper alloy for the intended use, die with inexpensive manufacturability and cheap mechanical Strengths has no nickel content.

The object is achieved by the use of a Copper-Titan-X alloy released from

2.0 to 3.5% titanium,
X = 0.1 to 1.0% iron or
X = 0.05 to 0.5% zircon or
X = 0.5 to 1.5% magnesium,
Remainder copper and usual impurities,

the vacuum-cast and extruded alloy after cold working, homogenization annealing between 850 and 1000 ° C (10 min to 10 h), rapid cooling with a cooling rate in the range from 20 ° C / s to 150 ° C / s and cold working between 50% and 90 % Degree of deformation has a hardness of at least 200 HV10
(the percentages of the alloy components refer to the weight).

Precipitation hardened binary copper-titanium alloys with Titanium contents of up to 4.3% by weight are already in use the microelectronics z. B. as connector, switching materials and relays because of their high strength and high Softening point as a class of material between phosphor bronze and viewed beryllium copper. Copper-titanium is generally considered to be Spring material.

Furthermore, for example from DE-PS 5 93 783 ternary copper Titanium alloys known. However, there is none Reference to the intended use.  

Also known for the production of eye edge profiles Cu-Ti2.0-Cr0.5 alloy achieves the desired property the sufficient residual hardness after connection work with Brazing, but is in the current discussion about the toxicological Effect of chromium alloy components for disposition. So z. B. in use containing chromium Welding caps of this type of alloy due to the risk of chromium oxide formation are increasingly being substituted. For a similar reasoning To prevent the manufacture of glasses, chromium can be used according to the invention can be replaced by iron, manganese or zircon.

The strength of this alloy class essentially becomes as determined by excretions in the binary CuTi system (see, e.g., A. W. Thompson, J.L. Williams in Metallurgical Transaction A. 15 (1984), p. 931 ff.).

By annealing between 300 and 500 ° C of the α mixed crystal if the cooling is not too fast, one runs first spinodal segregation. The excretions are first coherent. With increasing glow duration then orderly occur tetragonal β transition phases. An increase in hardness as a result the coherence tensions can be registered with The discontinuous separation sets an even longer glow duration the equilibrium phase β along the grain boundaries. An equilibrium phase arises above a limit temperature also as a Widmannstatten structure. The addition of Magnesium shifts the softening temperature to high values, because magnesium improves the solubility in titanium. iron has a grain-refining effect. The solubility of iron in copper is limited because of the sluggish course of the elimination process the hardening effect is also limited. Continuous and discontinuous CuTife excretions can be detected become.

The alloys are melted in a vacuum furnace. With the above According to the invention, alloy additives can have the properties with higher alloyed binary copper-titanium alloys up to 4.3% by weight of titanium can be achieved without the risk  the brittleness exists. Above 3.5% by weight of titanium the danger that even ternary alloys will not be hot formed can be.

The use is preferred embodiments of the invention a copper alloy according to the compositions recommended according to claims 2 to 4. According to claim 5 the copper alloy preferably undergoes a final cold working of at least 20%.

According to the invention, the copper-titanium-iron, copper Titanium-zirconium and copper-titanium-magnesium alloys for the optic wire processing industry, since they are nickel-free have excellent cold forming ability and in an inventive thermomechanical treatment high residual hardness after short-term annealing. Homogenized and work hardened wires can have a hardness of over 280 HV. After glowing in a salt bath for 30 seconds - with that the temperature effects of hard dissolving are simulated - are still hardnesses of over 150 HV10 at 700 ° C registered.

The processing of wire semi-finished goods into glasses according to the invention can with cold formed and homogenized semi-finished products be performed. Due to the rapid cooling, the homogenized state frozen. After one for the dimension and contour of the glasses part necessary cold working degree endangered then the final connection work by brazing not the desired spring properties according to the invention, which are characterized by a residual hardness of over 150 HV. Homogenized (900 ° C / 3 h / H₂O) and then cold formed Wires show soft annealed (700 ° C / 3 h / H₂O) and cold-formed wires after the higher residual hardness Softening annealing between 600 and 700 ° C.  

The invention is based on the following embodiment explained in more detail:

Bolts of the alloys CuTi2.5Fe0.5% by weight, CuTi2.5Zr0.1% by weight and CuTi2.5Mg1.0% by weight were added with a vacuum casting machine Cast cast bars with ⌀ 137 mm at 1140 to 1150 ° C. The overturned cast bolts were extruded into bars pressed with ⌀ 25 mm, the pressing temperature being 850 ° C. Then the sticks were over two three hour periods Intermediate annealing at 700 ° C rolled to a square dimension of 5.2 mm. 60% cold-formed, homogenized at 900 ° C, rapidly cooled (at approx. 100 ° C / s) and 60% finally Cold-formed wire rod is achieved by the HV10 hardness characterized:

This state results after 3 hours and 30 seconds Annealing at 650 ° C with the following residual hardnesses HV10:

This means that wires of the alloys mentioned meet the requirements the eyeglass frame manufacturer after softening behavior with Residual hardness of HV <150 after connection work with hard solder.

Claims (5)

1. Use of a copper-titanium-X alloy consisting of
2.0 to 3.5% titanium,
X = 0.1 to 1.0% iron or
X = 0.05 to 0.5% zircon or
X = 0.5 to 1.5% magnesium,
Remainder copper and usual impurities, the vacuum cast and extruded alloy after cold working, homogenization annealing between 850 and 1000 ° C (10 min to 10 h), rapid cooling with a cooling rate in the range of 20 ° C / s to 150 ° C / s and Cold forming between 50% and 90% degree of forming has a hardness of at least 200 HV10
for the production of wires and profiles for spectacle parts. 2. Use of a copper alloy according to claim 1 with 0.3 up to 0.6% iron for the purpose of claim 1. 3. Use of a copper alloy according to claim 1 with 0.1 up to 0.5% zircon for the purpose of claim 1. 4. Use of a copper alloy according to claim 1 with 0.8 up to 1.2% magnesium for the purpose of claim 1. 5. Use of a copper alloy after one or more of claims 1 to 4, which is a final cold working experienced at least 20% for the purpose Claim 1.